1. Field of the Invention
The present invention relates to knives for punching slots on cardboard blanks, and more particularly, to such machine that include removable knife assemblies.
2. Description of the Related Art
Conventionally, slots are punched on cardboard blanks by passing the latter in between cooperating and opposing wheels. One of these wheels includes one or more removable knife assemblies that penetrate inside a peripheral channel on the opposing wheel. The slots produced conventionally exhibit enlarged openings at the corners proportional to the thickness of the slots. The slots are typically 1/4", or preferably 3/8", wide in order to facilitate its handling by the automatic handling machines that bend the cardboard to form the boxes. If the slots are too thin, these automatic handlers jam causing slow downs in production. The wider the slots, however, the wider the openings at the corners. Therefore, a compromise is compelled.